1. Field of the Invention
The present invention relates to an index head in a semiconductor device test handler, and more particularly, to an index head in a semiconductor device test handler for mounting semiconductor device in a test socket at a test site.
2. Background of the Related Art
In general, modular ICs, in which memory, and/or non-memory semiconductor devices are fabricated on one substrate appropriately in circuit basis, are main components that serve important functions in computers or home appliances, which are shipped after various testing. As known, the handler is equipment required for automatic testing of the semiconductor device and modular RAM.
In general, many of the handlers are designed to carry out, not only a general performance tests under a room temperature, but also high temperature tests, and low temperature tests in which the semiconductor devices, the modular ICs, and the like are tested if they are operative normally under an extremely high temperature, or low temperature environment formed by using electric heater or liquefied nitrogen spraying system into a enclosed chamber at the test site.
In the meantime, the index head in the handler serves holding semiconductor devices in the test site under such an extremely high or low temperature, and mounting/dismounting to/from test sockets, as well as pressing down the semiconductor devices in a state the semiconductor devices are mounted in the test sockets for reducing contact resistances between the sockets and leads on the semiconductor devices.
The index head also serves to prevent a temperature drop of the semiconductor devices in the sockets during temperature testing by blowing hot air to the semiconductor devices in a state the index head presses down the semiconductor devices. However, the foregoing related art index head has the following problems.
First, in the hot air blowing for prevention of the temperature drop of the semiconductor devices, an accurate temperature control has been difficult, and even parts that require no heating are heated.
Second, the related art index head is provided with a compliance mechanism (or a floating mechanism) for an exact alignment between the held semiconductor devices and the sockets, which becomes shaky in high speed operation of the index head, that limits an operation speed of the index head.
Third, because a pressing down force of the index head on the semiconductors in the sockets influences a result of the test, it is required to control and monitor the pressing down force. However, the related art index head is not provided with devices for automatic control and monitoring the pressing down force, such that a worker is required to make sure and adjust the force, personally. Accordingly, an accurate control of the force has been difficult, and if the force is excessive, the semiconductor devices are damaged.